IP network address ranges - University of Cambridge & Associates

This is a list of IP addresses in use on the Cambridge University Data Network (CUDN). Please note that this does not necessarily imply that hosts on those addresses are to be considered part of 'The University of Cambridge and its Constituent Colleges', merely that they are connected to the CUDN and routed out to JANET / the Internet via the University's connection.

In particular, visitors may temporarily use addresses from the ranges listed below. In addition, member institutions (e.g. the Medical Research Council) may make use of addresses which would be considered 'part of the University' (e.g. 131.111.x.x) via proxy services or subsequent allocations.

If you have specific queries about this list and how it should be interpreted, please contact Network Support with your requirement.

It is strongly recommended that IP addresses are NOT used as a method of access control to internal or external services. Unentitled visitors or associate users may be permitted and entitled users on different addresses may be denied access incorrectly.

The following ranges of addresses are currently allocated to computers connected to the Cambridge University Data Network.

Public IPv4 addresses

128.232.0.0/16
129.169.0.0/16
131.111.0.0/16
192.18.195.0/24	Medical Research Council*
193.60.80.0/20
193.63.252.0/23	Medical Research Council*

* These ranges are used exclusively by Medical Research Council institutions but, as stated above, the MRC also uses some addresses in other ranges above.

In addition, the following addresses are used on the CUDN but computers using them should not normally be regarded as 'within the University' for access control purposes.

192.84.5.0/24

192.153.213.0/24

CUDN-wide private (RFC 1918) IPv4 addresses

172.16.0.0/13

172.24.0.0/14

172.28.0.0/15

172.30.0.0/16

Note that this amounts to all of 172.16.0.0/12 except 172.31.0.0/16, or alternatively all addresses from 172.16.0.0 to 172.30.255.255 inclusive.

See Private IP addresses within the University of Cambridge and the CUDN for instructions on the use of other private RFC 1918 addresses within the University.

Public IPv6 addresses

2001:630:200::/48

2001:630:210::/44

The CUDN is migrating from 2001:630:200::/48 to 2001:630:210::/44 during the summer of 2011 and into the academic year 2011/12. After this time it will use the latter exclusively and the former may be reassigned to another JANET-connected institution.

The 2001:630:210::/44 is intended to be subdivided, with certain areas marked out for non-local users (e.g. visitors from another academic site using eduroam). The details of this subdivision will be described once it becomes available. However, where possible, access control by IP address is NOT recommended, as with IPv4.

IPv6 is expected to be gradually deployed on the CUDN and public internet over the next few years, probably with an aim to replace IPv4 over the next 10 years or so.

Last updated: September 2011